Rotary pump



C. F. WAITE ROTARY PUMP Filed April l0. 1930 July `12, 1932.

f 1.,/ A w l Patented July 12, 1932 UNITED STATES PATENT ol-*lucaACHABLES'F. WAITE, OF SOMERVILLE, MASSACHUSETTSLAS-SIGNOB 0F ONE-HALF'TARCHIBALD W. JOHNSTON, OF BRIDGEPOBT, CONNECTICUT ROTARY PUMP applicati@inea April 1o,

The present invention relates to rotary pumps and more particularly torotary pumps oi` the general types' disclosed in my co-pendingapplication Serial No. 432,061, iiled Februar 28, 1930. f

The o ject of the present invention is to provide improvements in rotarypumps with a'particular view toward smoothness of operation.

With thisl object in view, the principal feature of the presentinvention comprises a rotary pump having a rotor, a piston reciprocatingdiametrically in the rotor, and eccentric positioning means for thepiston, to-

gether with means whereby relative movement between the piston and theeccentric positioning means is availed of to complement the discharge ofthe piston. This complementary discharge is arranged to occur out ofphase with the discharge brought about by the reciprocation of thepiston,whereby an overlap of discharge eflectA is obtained,

tending to smooth out any pulsations which mi ht exist in the outlet.

ther features of the invention consist in certain novel features ofconstruction, combinations and arrangement of parts hereinafterdescribed and particularly defined in the sectional end elevation of oneform of pump according to the present invention; Fig. 2 is an endelevation of the pump shown in Fig. 1 with the end plate in place; Fig.3 is a sectional side elevation of a modified and in some which engageswith-the cylindrical surfaces ,14 and 16 of the casing, and iscounterbored to provide an' inner 'cylindrical surface 18.

The rotor is also provided with a diametrical In the accompanyingdrawing, Fig. 1 is a 1980. `Serial No. 443,054.

- ecc'entrically of the rotor axis.

casing is provided with portsA The pum or clockwise rotation of the ro-32 and 34.

tor, the ports 32 and 34 are respectively inlet and outlet ports.

The construction thus far described is similarto thatdisclosed in myco-pending applicati-on Serial No. 424,208. According tothe presentinvention, the walls of the rotor areprovided with a series of radialopenings indicated at 36v and 37. The chambers included between-the endsof the shuttle block 24 and the internal surface 18 of the rotor undergovariations in volume, due to reciprocations of the shuttle block withrespect to the piston, and these variations of volume are made use of toeffect va discharge which is comple.- mentary to and out of phase withthe main discharge of the piston 20. It will be seen from Fig. 1 thattwo of such internal chambers are provided, one of which is indicated at38 and the other at 40. Upon rotation of the rotor in a clockwise'direction from the position of Fig. 1, the chamber 38 will increase involume and fluid will be drawn into it through the openings 36, whereasthe chamber 40 will decrease in volume and the Huid contained thereinwill be forced outwardly through the openings 37. The chamber 38 willcontinue to increase in volume and the chamber 40 will decrease during180 rotationl of the rotor. The openings 36 and 37 are so disposed astospan the cylindricalsurfaces 14 and 16 of the casing, so thatimmediately upon advancement from the indicated position, the'leadingsuction opening 36 will draw fluid into the space 38 and the leadingdischarge opening 37 will have `liquid forced out through it. Duringthisoperation, the

piston 20 acts in its normal manner, as described in the co-pending aplication, givv mg a pumping stroke for eac rotation of the rotor. Themain and complementary pum ing eiects obtained by the iston and y thechanges in volume of t e cham- `bers 38 and 40 are outofphaseby 90.Therefore, the maximum complementary pumping eiect occurs at a time whenthe mam pumping eiect is zero, andvice versa. Therefore,

.ing 'ferred According to'this construction, the

`which reciprocations take place along axes at right angles toeachother. The piston reciprocates along the axis of the diametricalgroove of the rotor, and the shuttle reciprolcates in eiect along theaxis of the transverse groove of the piston.

The eccentric pin 28 may be ixed in posi- 'l tion, but where it isnecessary to vary the 'volume of discharge or to maintain a con stantpressure under varying conditions, the adjustable eccentric described inmy oo-pendapplication Serial No. 432,061 is preend plate 42 of thecasing is provided with a chamber 44 having a plunger 46 which carriesthe eccentric pin 28. The plunger is acted upon by a spring to urge t epin into eccentric position. -Two control openings 52 and 54 which arecored in the end plate connect respectivel with the dischargle and inletof the pump. increase of disc arge pressure acts through the opening 52to depress the plunger 46 and thus to move the pin 28 into a. positionmorenearly concentric with the rotor, thereby reducing the discharge.The openin 54 is provided to bleed the space below the unger46 of any liuid which may leak past t e plunger. It will 4e seen that the adjustableeccentric acts upon both the main and auxiliary pum ing means in asimilar manner. Thus, as e yeccentric is moved towards its centerposition, the stroke of the piston 20 is decreased and moreover,` thevariand do not vary as condltion, the rotor atlons 1n the volumes of theinternal chambers 38and 40 are diminished. When the eccentric reaches aposition concentric with the rotor, the piston 20l remains in its mid"le position and does not reciprocate in the rotor. Also, the spaces 38and 40 are of equal volume the rotor rotates. In this rotates` idlywithout pumping any uid. It will be. noted that under such conditions,agitation of the Huid.

The pump marked im rovement in the smoothness of discharge" tlhrough theoverlappingV 'of the main and complementary discharges. Inasmuch as thecomplementary discharge, however, is less than the main discharge,pulsations may not be entirely lavoided.

there is practically no described above produces a` still i furtherimprovement in the smo thness of operation may be attained by theconstruction shown in Figs. 3 to 6, wherein pumping eiectspra'cticallyequal in magnitude but out of phase with eachother are produced. In

this construction, the casing 8 and end plate 42 are-identical withthose described above. The rotor iss/imilar to the rotor 10 except thatit is not required to be counter-bored. l

The rotor'is continuouslyv driven by a shaft 61. A diametricall groove62 having parallel walls is provided, as before.v The plston 64comprises an integral structure having two curved end pieces 66connected by a web 68 of considerably less depth and Width than the endpieces. The shuttle 70 is of the same length as the web 68 but issomewhat narrower than the piston. The shuttle is pron vided with anundercut groove 72 of greater width than the web 68, whereb the shuttlemay tit over the web 68 but out o engagement therewith, lso that/arelative reciprocating movement between the piston and the shuttle maytake place. The shuttle/has an opening 74 to receive the eccentric pin28. Each edge face 76 of the shuttle block has a pumping 'areasubstantially equal to the effective pump- .ing area of each face of thepiston. The r0- tor is provided with a plurality of radial openings 78.As shown 1n Fig. 3, a number i of these openings may be arrangedlongitudinally of the rotor. As shown in Fig. 5, the vinternal chambers'82 and 84 between the shuttle and the rotorl un ergo variations involume as the rotor rota es. In Fig. 4 the space 82 is reducedpractically to zero and the s ace 84 is of maximum volume. In turning cockwise into the position of Fig. 5, the space 82 'increases in volume,thereby sucking liquid from the inlet, and the space 84 diminishes involume, thereby forcing liquid into the discharge. The stroke of theshuttle is measured by the combined width ofthe passages 82 and 84. Forequal pumping eiects, the

stroke and etlective area of the iston 6() and of the shuttle 70 areequal. y this construction, the overlapping of equal discharges whichare half a stroke out of phase with each other produces a practicallyuniform pressure in the outlet. inasmuch as the internal space under theshuttle 70 may eventually become filled with liquid, the web 68.is madeof reduced 'depth to provide a clearance space 86. As shown in Fig. 3,when the shuttle reciprocates with respect to the piston, the fluidwhich may be trapped in the groove 72 is .free to iiow over the web 68from one side to the other thereof,

seen, as in the case of the pump ofFi 1 and 2, that the adjustableeccentric a ords particular advantages inthat it etfectually controlsboth the main and complementary pumping actions. Thus, as the eccentricis moved toward the central position, both the piston and the shuttleare brought toward their middle orv inactive positions.

Havin thus described the invention, what is claimed is: 4

1. A rotary pump having, in combination, a rotor, a piston mounted forreciprocation in said rotor and provided with a groove, eccentricpositioning means in said groove reciprocating with respect to thepiston, passages in said rotor leading to an internal pumping chamberdefined by surfaces of the rotor'and said eccentric positioning means,whereby the reciprocation of said means relatively to the rotor surfaceproduces a pumping effect complementary to the operation ofthe piston.

' 2. A rotary pu`mp having, in combination, a rotor, a piston mountedfor reciprocation in said rotor and provided with a transverse groove, ashuttle block received in the transverse groove, means for maintainingthe shuttle block eccentrically of the y rotor whereby rotation of therotor causes pumping `reciprocation of the piston relatively thereto andof the shuttle relatively to the piston, passages in said rotor leadingto an internal pumping chamber defined by surfaces of the rotor andshuttle whereby the reciprocation of the shuttle relatively to the rotorsurface produces a pumping effect complementary to the operation of thepiston.

3. A rotary pumpv having, in combination, a rotor, a piston adapted toslide radially lin said rotor, a shuttle adapted to slide radiallyl insaid piston, the directions of movement otthe piston and shuttle beingat right angles to4 each other, a pivot eccentrically maintained in thepump and carrying said shuttle, whereby ,rotation of the rotor causesreciprocation of the piston and shuttle relatively to each other and therotor, an internal pumping chamber in said rotor defined by walls of therotor and said shuttle whereby the reciprocation of the shuttle causes,by its movement relatively to the rotor wall2 a pumping -effectauxiliary to that of the piston.

` 4. A rotary pump having, in combination,

Va rotor having a diametric passage, a piston reciprocating inthe'passage and provided with a transverse groove, a shuttle blockreceived in the transverse roove, means for pivoting the shuttle bloceccentrically of the rotor whereby rotation ofthe rotor causesreciprocation of the piston relatively, thereto and of the shuttlerelatively to the piston,.ad ditional passages through said rotorleading into an internal pumping chamber defined' by surfaces of the'shuttle and rotor, whereby movement of the shuttle during rotation ofthe rotor produces a umpng eEect complementary to and out o phase withthe pumping eiect of the piston.

5. A1 rotary pump having, in combination, a rotor, a piston mounted forreciprocation in said rotor and provided with a groove, eccentricpositioning means in said groove reciprocating with respect to thepiston, passages in said rotor externally spanning substantially thesame arc asthe iston andlead'- ing to. an internal pumping c amberdefined by surfaces of rthe rotor and said eccentric positionin means,whereby the reciprocation of said means relatively to the rotor surfaceproduces a pumping effect complen groove, a shuttle block received inthe transverse groove, means for maintaining the shut- Y tle blockeccentrically of the rotor whereby rotation of the rotor causes pumpingreciprocation of the piston relativelysthereto and of the shuttlerelatively to the piston, passages in said rotor externally anningsubstantially the same arc as the piston and leading to an internalpumping chamber defined by surfaces of the rotor and shuttle whereby thereciprocation of the shuttle relatively to the rotor surface produces apumping effect complementary to the operation of the piston.

7. A rotary pump having, in combination, a casing having inlet andoutlet chambers and sealing surfaces between the chambers, a rotorhaving a diametrical opening, a piston reciprocating in said opening andhaving a transverse groove, a shuttle block in the groove of the piston,means for maintaining the shuttle block eccentrically ofthe rotor,

tively thereto and of the shuttlerrelatively to the' piston, theinternal surfaces of the rotor and the shuttle forming chambers ofvariable volume,4and the rotor having passages leading from saidchambers and displaced from the transverse groove and externallyspanning substantially the same arc as the piston.

8. A rotary pump having, in combination, a rotor, a piston mounted forreciprocation in saidl rotor and provided with a transverse groove, ashuttle block received in the transverse groove, means for maintainingthe shuttle block eccentrically of the rotor whereby rotation of therotor causes pumping reciprocation of the piston relatively thereto andof the shuttle relatively to the piston, passages in said rotor leadingto an internal pumpingr chamber defined by surfaces of the rotor and theshuttle and piston, whereby therreciprocation of the shuttle relativelyto thev rotor surface and the piston produces a pum ing piston.

9. A rotary pump having, in combination,

a rotor having a diametric passage, a, piston reciprocating in thepassage and rovided with atransverse groove, a shuttle lock received inthe transverse groove, means for pivoting the shuttle blockeccentrically of the rotor' whereby rotation of the rotor causesreeiprocation of the piston relatively thereto the rotor wherebyrotationof the rotor causes reciprooation of the piston relativel thereto andofthe shuttle relatively to the-piston, the reciprocation of saidshuttle relatively to the piston being limited by the Walls of the rotorening the diametrlc passage, additionall passages through saidrotorleading into the I0 internal pumping chamber dened by the sur faces ofthe shuttle and rotor and piston, whereby movement of the shuttle duringrotation of the rotor produces a pumpin effect complementary to andoutof phase with the 35 pumping effect of the piston.

11. vA rotary pump having, in lcombina tion, a rotor, a. piston mountedfor reciprocation in said rotor and .provided with a transn versegroove, a shuttle block received in the transverse roove, means formaintaining the shuttle bloc eccentrically of the rotor where= byrotation of the rotor causespumping Vrecxprocation of the pistonyrelatively thereto passages'in said rotor leadingtoan internal y pumpmgchamber dened bysurfaces of the rotor and shuttle whereby Ythereciprocation of the shuttle relatively' to the rotor surface produces apumping effect complementary to the operation of the piston, and meansfor ad- ]usting the .eccentrioity of said 'shuttle block to control boththe main and complementary pumping eects.

12. A. rotary pump having, in combination, a. rotor, a piston mountedfor 'reciproca- 1 tion in said rotor andprovided with a groove,eccentric positioning means in said groove reciprocating with'respect tothe piston, passages in said rotor leading to. an internal l andof theshuttle'relatively to the ipiston,"

shuttle whereby the reciprocation of the shut- 'ously to control bothpum and of the shuttle relatively to the piston,

A pumping chamber defined by surfaces of the? rotor, and sa1d`eccentricpositioning means,

centricity of said positioning means to oon;-

- trol both the main and complementary pumping effects.

' 13. Arotary pump having, in combination, a rotor, a piston Imountedfor reciprocation in said rotor and provided with a groove, ec\ centricpositioning means in saidfgroove reelprocatlng with respect to thepiston, passages in said rotor leading to an internal pumpingv chamberdefined by surfaces ofthe rotor, and said eccentric positioning meawhereby the reciprocation of said means relativel to the rotor surfaceproduces a pumping el ect complementary to the operation of the piston,and means controlled bythe discharge' pressure to vary the eccentricityof the positioning means and thereby simultaneously to control bothpumping ei'ects.

14. A rotary pump having, in combination,

a rotor, a piston mounted for reciprocation in said rotor and provided.with a transverse groove, a shuttle'block received in the transversegroove, means for maintaining the shuttle block veccentrically of therotor whereby rotation of the rotor causes umping reciprocation of thepiston relative y thereto and off the shuttle relatively to the piston,passages in said rotolgleading to an internal pumping chamber dened bysurfaces-of the rotor an tle relatively to lthe rotor surface produces at complementary to the operapumping e ec tion of the piston, and meanscontrolled by the discharge pressure tovary the eccentricity im' of saidshuttle block and thereby simultaneing effects.

In testimony whereof have signed my name to this specification.

' CHARLES F. WAITE..

whereby the reciprocation of said `means relativelg to the rotor surfaceproduces a pumping e ect com lementar to the operation of u' the piston,an means or'adjusting the ec-

